The present invention relates to the measurement of the speed of sound in liquids, and more particularly to identifying an unknown liquid by determining the speed of sound in the liquid and correlating the speed with known liquids having known speeds of sound.
There are many applications where identification of liquids in bulk containers is required. One example of such an application is the identification of liquid filled containers located in industrial storage yards or waste sights. For example, the United States Customs Department has the need to identify may types of bulk liquids at U.S. ports of entry for purposes that include export control or identification of contraband.
Presently, identification of liquids stored in sealed containers, such as 55 gallon steel drums, requires breaching the integrity of the container and physically sampling the liquid. However, opening a container and performing the tests necessary to identify the liquid content is very time consuming and potentially dangerous. Exposure to many of the liquids encountered in such inspections may present hazards to human health. Therefore, a need exists for a simple non-contact method for identifying such liquids.